<!DOCTYPE html>
<html >
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>语句</title>
</head>
<body>
    
</body>
<script>
    let age=29;
    if(age<=18){
        console.log("小朋友");
    } else if(age<=50){
         console.log("大哥大姐");       
    }else if(age<=60){
         console.log("大叔大婶");       
    }else{
        console.log("大爷大妈");
    }
</script>
</html>